Compose pointer to property of object

McLion

Getting forward :-)
The hint with the sender in the signal was great too. As if you would know before, I really stumbled over this - thanks!

I came across an issue with the list though.
There are no absolute positions in the list. Saying if 3 entries are made (0,1,2) and the second list (1) is cancelled for instance because it's not needed anymore, former entry 2 becomes entry 1.
QList seems to always fill from the 0 up and there are no absolute positions.

I either did not get all of QList or I may need to switch to some other solution - unfortunately- because it otherwise works a treat.

mrjj

hi
Im not sure what wrong with QList since its dynamic and
we cant have invalid pointers around ?
else use a map
http://doc.qt.io/qt-5/qmap.html
QMap<int,QWebView * > map;
QWebView *webGUI = new QWebView(this);
...
map[1] =webGUI ;
map[2] =nextwebGUI ;
...
QWebView *w=map[2]; // it will stay "2"

They wont change position as 1,2 is a key
like map["onekey"] =webGUI ;
but we use int as no need for string.
so even if we remove map[1] then
map[2] is still there.

So maybe it works better for you ?

McLion

Tried quickly ... and the Map is exactly what I need.
Thanks a million! .... I'll be back ;-)

mrjj

@McLion
super
notice if you reuse the key
map[1] =webGUI ;
map[1] =nextwebGUI ;
It will replace the web *.

McLion

Thanks for the heads-up.
I'll do some testing and experiment.

McLion

So far, everything related to this threads question and the QMap as solution seems to work.

I stumbled over something else while relacing the QwebView from the Designer by my 'on-demand' created one:
I can not load an url, it crashes with sig11.

I get the following connect error on bootup:

QMetaObject::connectSlotsByName: No matching signal for on_webGUI_loadFinished(bool)

which I dont understand and may be the cause.
I have connected:

connect(webGUI, SIGNAL(loadFinished(bool)), this, SLOT(on_webGUI_loadFinished(bool)));

and in *.h as private slot:

void on_webGUI_loadFinished(bool arg1);

This worked before, with the QWebView from the Designer.
Any idea? Thanks.

mrjj

@McLion said:

no matching signal for on_webGUI_loadFinished(bool)

Hi
this warning comes as you name slot on_XXX
This will trigger Qt auto connect feature so when you use
a concrete connect you should rename it so it dont
start with on__
(right click it- refactor->rename)

also please do
qDebug() << "loadfin:" << connect(webGUI, SIGNAL(loadFinixxxx

to see if it returns true; ( as in , it can connect)

McLion

I wasn't aware that using on_ in the name will trigger any functionality!
Refactoring solved this problem - Thanks !

However, the signal 11 crash when trying to load an url seems to have some other cause .... I'm searching ;-)

jsulm

You're most probably dereferencing a null pointer. Signal 11 means SIGSEGV (segmentation error).

McLion

@jsulm
Yes - Thanks . Problem loacted, but not yet solved:

void QTGUI_MainWindow::populateJavaScriptWindowObject()
{
  QWebView * webGUI = qobject_cast<QWebView *>(sender());
  webGUI->page()->mainFrame()->addToJavaScriptWindowObject("NativeBridge", this);
}

The sender is the JS and not the QWebView and so I do not get the pointer to the QWebView that I need. Instead, the pointer is 0x0 and then - of course - the addToJ... crashes.

Any idea how I get the pointer to the QWebView from which the JS is sending?
Thanks

jsulm

What is JS?

McLion

@jsulm
JavaScript (in/from QWebKit ... more precise page()->mainFrame().

McLion

I posted this as a separate question in the WebKit group.

McLion

Got it solved :-)

QWebFrame * webGUIframe = qobject_cast<QWebFrame >(sender());
QWebView * webGUI = (QWebView)(webGUIframe->parent())->parent();
webGUI->page()->mainFrame()->addToJavaScriptWindowObject("NativeBridge", this);